Steam boiler



July 21 W25.

A. W. HARRIS STEAM BO ILER 2 Sheets- Sheet 1 Filed Feb. 21, 1923 g di g-0:0;

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July 21, 1925.

A. HARRHS STEAM BO ILER 2 Sheets-Sheet 2 xmswmmmmwmxw 4W Filed Feb. 21, 1923 E Iiwa 0775626 r6022 ZI XZZQzrrzb;

Patented July 21, 1925.

UNITED STATES PATENT OFFICE.

mnnson w. imam, or NORTH onnr'ranooon, mnmwnssnn.

STEAM BOILER.

Application filed February 21, 1923. Serial No. 820,411.

certain new "and useful Improvements in Steam Boilers, of which the following is a full, clear, and exact specification.

This invention relates to inverted refrac tory arches for protecting the girth seams and other parts of. the shells of return tubular and other types of steam boilers.

While one \of' the main objects of the invention is to protect the girth seams of boiler shells, other objects are to utilize the inverted arches for promoting more complete combustion and for replacing the overhanging front walls commonly used for protecting the frontends of such shells, and to provide for circulating water through the supports for said arches so that said supports and said arches will last longer than they would otherwise. In order to promote combustion the arches are arranged at intervals along *he boiler shell and in front and rear of th bridge wall, so that the gases or products of combustion must travel a tortuous passage resulting in a more complete mixing thereof with the air than is possible when the arches cover the entire bottom of the boiler shell. The arches according to the present invention are accordingly placed in such a manner as to serve as an ignition or coking arch over the furnace and also to promote the consumption of smoke while increasing combustion.

The overhanging front walls commonly used at the front of boiler settings are a source of annoyance and expense to keep up and when not kept up the gases will be short-circuited in what is known as a flush ended boiler, and in the case'of a shell extension boiler the" extended part of the shell is left unprotected and is apt to burn and crack, said cracks often extending back be-v yond the front head and seriously damaging the boiler. By utilizinga water cooled inverted arch in pl e ofan overhanging front wall in accordaiibh with the present invention the annoyance and trouble referred to is avoided because such arch will out last many overhanging front walls.

porting them in place, so that a section of an arch or a complete arch may be renewed from time to time as may be required without employing skilled labor. The design and arrangement of the tiles is such that they may expand and contract without causing strains on the boiler shellor the water circulating supported.

A further object is to promote the circulation of water from the boiler shell throughthe supports for the arches without pipes on which said tiles are reducing the efficiency of the shell to aniundesirable extent. Other objects will appear as thedescription proceeds.

The invention will be first hereinafter described in connection with the accompanying drawings, which constitute part of this specification, and then more specifically defined in the claims at the end of the description.

In the accompanying drawings, wherein similar reference characters are used to des ignate corresponding parts throughout the several views Figure 1 is a side elevation of a return tubular boiler shell with the setting for said. shell and the arches arranged in accordance with this invention shown in section, the rear end of theshell being broken away.

Figure 2 is a section on the line IIII of Figure 1. i

Figure 3 is a detailed section through the shell and one 'of the arches on an enlarged scale to illustrate the way in which the sections' or tiles of said arch are formed to allow. for expansion and contraction, and

Figure 4 is a broken view of the front end portion of a shell extension boiler with its setting and an arch to replace the usual setting of the boiler may or may not have the usual bridge wall 3 at the rear end of the grate 4.

Each of the refractory inverted arches 5, of which six are shown in Figure 1, comprises a plurality of tiles, blocks or sections 6 made of suitable heat resisting or refractory material and formed. generally hookshaped with a notch 7 opening on its upper surface and extending below an overhanging lug or extension 8 having a substantially horizontal or slightly curved under face adapted to engage and hang over a water pipe 9 by which the arch is supported in position under, the boiler shell. The water pipe 9 for each arch extends concentric to the 1 boiler shell and communicates with the in: terior of said shell at opposite sides thereof on different levels, as shown best in Figure 2, so as to create an unequal head of water \and cause circulation of some of the water 115 from said shell through said pipe. fh-us, the connection 9 of each water pipe on one side of the shell is higher than the connection 10 of said pipe with the other side of the shell, but both connections are preferably below the water line of the shell. This circulation of the water from the shell through the supporting pipes 8 of the arches 5 protects ,the metal, in the supports from overheating, thereby greatly increasing the durability of the arches as compared with those mounted on supports through which water is not circulated. When a plurality of arches are used, as shown in Figures 1 and 2, the supporting pipes 9 therefor have alternating high and low connections to the shell on both sides so as not to reduce the efliciency of the shell to an undesirable extent by having holes in same spaced too close together on the same line The-tiles 6 are formed one end of each of them is normally spaced from the shell. at 11, Figures 1 and 3, while the upper face of the overhanging lug or extension 8 ,of each tile i s inclined at 12 so that only the'end portion of the tile adjacent said lug norm-ally contacts with said shell, leaving room\ for said tiles to rock on the Supporting water pipes under expansion or I contraction without placing strains on the shell or pipes, It will be noted also that the tiles are simply hung on or over the supporting pipes, no bolts being used for binding said tiles to thepipes or to the shell, so that it is an easymatter for unskilled workmen to remove and replace the tiles in a portion of an arch or in an entire arch whenever required. Furthermore, the

absence of bolts piercing the shell for fastening the sections of the arches thereto is an important improvement over prior constructions because the tapped. holes for said bolts tend to weaken the shell.

The. arches 5 are placed so as to protect the girth seams from the direct action of-the fire, and at. the front end of the shell the arch which protects the end seam takes the place of the usual-overhangingwall in the extension shell type of boiler illustrated in shown iniligure 1. in Figure at the parts as shown so that Figured as well as in the hush ended type' age shown are designated by the same reference characters as in Figure 1, the extension end of the shell being indicated at 13, in Figure {1, while the flush end or head of the boiler shell in Figure l is indicated at 14-. v

The arches 5 may also be placed at suitable intervals along the bottom of the shell to form ignition or coking arches and compelling the gases or products of combustion to travel a tortuous passage under said shell so as to cause said gases to become thoroughly mixed with the air to the end that complete combustion may be promoted and the smoke consumed. As shown in Figure 1, one or more of the arches may be placed in front and in rear of the bridge wall 3, and if desired,- said arches may also be placed over the bridge wall. A plurality of said arches may also be arranged over If desired, the supporting pipe 9 for the arches may. communicate with the interior of the shell, as indicated; at 15 in Figure 2, but the connection of'the ends of said pipes with the shell may be sufficient and preferred.

1 It will further be understood that the term tiles used in this specification and in the claims appended hereto is intended to include blocks, bricks and any other sections .'of the arches no matter of what kind of .re-

fractory material they may be made.

I claim:

1. The combination with a boiler shell, of an inverted refractory arch for protecting a portion of its under surface, said arch comprising a support spaced from the shell and a series of refractory tiles each having a notch in its upper face and a lug overhanging'one end portion of said notch and extending, between the support and shell, the upper edge of said lug being inclined and the inner end of said lug and the other end ofthe tile being normally spaced from the shell, whereby said tiles may rock on the support under expansion or contraction for the purpose specified 2. The combination with a boiler shell, of an inverted refractory arch for protecting a portion of its under surface, said arch comprising a support spaced from the shell, and i a series of refractory tiles each having a notch in its upper face and la lug overhanging one end portion of said notch and extending between the support and shell, the

lib

. imaaeao other end of each tiie extending upward above said support to a point adjacent the boiler shell.

a The combination with a boiler shell, a

an inverted refractory arch for protecting a portion of its under surface, said arch comprising a tubular support spaced from the shell and a series of refractory tiles each having a notch in its upper face'and a lug overhanging one end portion of said notch and extending between the support and shell, the upper edge of said lug being inclined and the inner end of said lug and the other end of the tile being normally spaced from support under expansion or contraction, and means .for circulating Water from the shell through said tubular support.

4. In adevice of the class described, a support, a tile for said support comprising a body having an inclined upper face an angularly disposed notch entering said face and terminating nearer one end thereof than the other, said notch providing an overhanging lug, and the breadth of said notch beneath said lug being greater than the breadth of said support.

In testimony whereof I have signed my name to this specificatien ANDERSQN We HARRIS: 

